13.FUNCTIONS TO SIMPLIFY PROGRAMMING PROGRAMMING B-63324EN/03
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- Spindle rotation
Before G74 is specified, turn the spindle in the reverse direction with a
miscellaneous function (M code).
When successive hole machining operations which involve a short
distance from a hole position and the initial level to the R point level,
the spindle may not reach the normal speed before starting a hole
cutting operation. In such a case, L for the number of repeats must not
be specified. Instead, a dwell time based on G04 must be inserted
before each hole machining operation. However, some machines do
not require this specification. For details, refer to the manual provided
by the machine tool builder.
- Miscellaneous function
When the G74 command and an M code are specified in the same block,
the M code is executed at the time of the first positioning operation.
When L is used to specify the number of repeats, the M code is
executed for the first hole only; for the second and subsequent holes,
the M code is not executed.
- Tool length compensation
When a tool length offset (G43, G44, or G49) is specified in the canned
cycle, the offset is applied at the time of positioning to point R.
- Axis switching
Before the drilling axis can be changed, the canned cycle must be
In a block that does not contain X, Y, Z, R, or any other axes, drilling is
Specify R in blocks that perform drilling. If it is specified in a block
that does not perform drilling, it cannot be stored as modal data.
Do not specify a G code of the 01 group (G00 to G03 or etc.) and G74
in a single block. Otherwise, G74 will be canceled.
- Tool offset
In the canned cycle mode, tool offsets are ignored.